ACT English Question

The Met is [basic] in limiting the amount of artwork publicly displayed in its galleries. Art museums usually display less than 10 percent of their artwork at any one time.

A. No Change
B. run-of-the-mill
C. fairly typical
D. medium

The answer is C. But can anyone explain why.

Also this one:

Artwork that isn’t on display gets relegated to out-of-the-way storage areas with few or no environmental controls. Variations in light, humidity, and temperature [can damage] the art.

A. No change
B. has damaged
C. is damaging
D. damages

Answer is A.